Waterline thermostat and assembly

ABSTRACT

An improved thermostat and mounting assembly therefor wherein the power member of the thermal power unit is received within an especially configured stirrup which provides a streamlined flow pattern over and immediately upstream of the stirrup. The flow pattern established prolongs the life of the thermostat by reducing stirrup erosion while also improving the flow characteristics of the thermostat. In accordance with another feature of the invention safe assembly of the thermostat within the flow conduit is assured by an especially configured transverse wall piece of the thermostat locking into an interference fit with an especially configured outlet casting in the flow conduit.

United States Patent Obermaier et al. 5] Nov. 4, 1975 WATERLINETHERMOSTAT AND 3,173,609 3/1965 Obermaier 236/34 ASSEMBLY 3,448,9216/1965 Kelly 11 236/34 [75] Inventors: Frank E. Obermaier Lombard Prim,

ry Examzner-Edward G. Favors Arthur A. Scott, Mount Prospect, both of mAttorney, Agent, or Fzrm Teagno & Toddy [73] Assignee: EatonCorporation, Cleveland, Ohio ABSTRACT [22] Filed: Jam 4, 1973 Animproved thermostat and mounting assembly therefor wherein the powermember of the thermal PP N05 321,101 power unit is received within anespecially configured [44] published under the Trial Voluntary Proteststirrup which provides a streamlined flow pattern over Program onJanuary 28 1975 as document no and immediately upstream of the stirrup.The flow B 321,101 pattern established prolongs the life of thethermostat by reducing stirrup erosion while also improving the 521 US.c1 236/34; 236/100 characteristics of the thermostat [51] Int. Cl. F01P7/16 In accordance with another feature of the invention [58] Field ofSearch.... 137/219, 220; 236/34, 34.5, safe assembly of the thermostatwithin the flow 236/100 conduit is assured by an especially configuredtransverse wall piece of the thermostat locking into an [56] ReferencesCited interference fit with an especially configured outlet UNITEDSTATES PATENTS casting in the flow conduit.

l,936,650 11/1933 Wade 137/220 6 Claims, 4 Drawing Figures US. PatentNov. 4, 1975 Sheet 1 of2 3,917,163

WATERLINE THERMOSTAT AND ASSEMBLY This invention relates to thermostatsof the poppettype and more particularly to the construction of suchthermostats which tend to increase the life, efficiency, and assemblythereof.

The invention is particularly applicable to a poppettype waterlinethermostat which is disposed within the conduit of a cooling system of avehicle to control the flow of fluid through the engine in response tothe temperature of the fluid and will be described with particularreference thereto. However it will be appreciated that the principles ofthe invention may have broader application and may be employed in anytype of valve assembled in a conduit for controlling unidirectional flowof fluid therethrough.

Thermostats of the type to which this invention relates generallycomprise a transverse wall piece from which extends an annular mountingflange. A ported valve seat formed within the transverse wall piecereceives a temperature sensitive power unit which extends therethrough.The power unit has a relatively movable portion or casing connected to avalve which cooperates with the valve seat to open or close the flow offluid through the conduit. A guide base wall portion appending from oneend of the transverse wall piece guides the casing during its movementwhile also functioning as a spring seat for a spring which biases thevalve into seating engagement with the valve seat. Extending upwardly onthe other end of the transverse wall piece is a stirrup formed from anelongated narrow piece of stock bent along its longitudinal axis toprovide a fixed stop for the end of a power member which extends fromthe casing of the thermal unit and abuts against the stirrup. Relativemovement between the power member and casing causes the valve to moveout of engagement with the valve seat permitting coolant flow to passtherethrough.

The coolant flow which is turbulent directly impinges against thestirrup to such an extent that stirrup failure results, rendering thethermostat inoperative. Thus the coolant employed in an engine isactually a slurry composed of core sand, anti-freeze, water and otherforeign matter which directly impinges against the stirrup when thethermostat is opened and eventually erodes the stirrup to the extentthat failure occurs. Attempts to correct this condition by increasingthe cross-sectional thickness of the stirrup have proved unsatisfactory.Also, while satisfactory results have been achieved when employing astirrup formed from wear-resistant material such as stainless steel, thecost of such thermosta ts'is generally considered prohibitive.

Furthermore when the thermostat is assembled into the flow conduit, itis initially placed in an opening in the water jacket which defines thedownstream or high pressure portion of the conduit. The outlet castingwhich defines the upstream or low pressure portion of the flow conduitis then positioned over the top of the thermostat and bolted into thewater jacket to secure the thermostats annular mounting flangetherebetween. Because of the configuration of the outlet casting whichis dictated by engine design and also the play ofthe thermostat in thewater jacket opening, the thermostat is not infrequently renderedinoperative during positioning and bolting of the outlet casting as aresult of distortion of the power member and the stirrup.

It is thus a principal object of the subject invention to provide athermostat having an especially configured stirrup which resists erosionwhile also providing a thermostat mounting arrangement which permits thethermostat to be assembled in a flow conduit without damage thereto.

In accordance with the invention there is thus provided a thermostatcomprising a transverse wall piece having formed therein a ported valveseat. Disposed within and extending from both ends of the transversewall piece is a temperature sensitive power unit comprising a powermember at one end and a casing portion at the other end. Secured to thecasing portion is a valve member cooperating with the ported valve seat.Appended to one end of the transverse wall piece is a base wall portionwhich serves to guide the casing portion of the power unit while alsohousing a spring which biases the valve into a normally closed position.Extending from the other end of the transverse wall piece is a stirruphaving a formed apex spaced from the center of the opening in thetransverse wall piece to receive the tip of the power member. Thestirrup is further defined as having at least two contiguous formedportions extending from the apex to the end of the transverse wallpiece. The formed stirrup portions are characterized by having asubstantially closed, crosssection profile which streamlines the coolantflow around the stirrup to prevent direct impingement thereagainst.

In accordance with another feature of the invention the transverse wallpiece is further defined as having an annular flange at one of its endsand an upwardlyextending sleeve portion spaced radially-inwardly fromand contiguous with the flange. The sleeve portion is generally circularand defined by a first predetermined minor diameter. At least oneprotrusion extends outwardly from the sleeve portion to define a second,major sleeve diameter. The outlet casting which receives a portion ofthe thermostat to define the upstream or low pressure side of the flowconduit has an elliptical base opening which contacts the thermostatssleeve portion. In particular the sleeve portion is fitted into the baseopening of the outlet casting with major and minor diameters alignedrespectively and twisted into an interference holding condition wherebythe thermostats major diameter is aligned with the minor diameter of thebase opening in the outlet casting.

It is thus an object of the present invention to provide a thermostathaving an especially formed stirrup portion thereof which increases theoperating life of the thermostat.

It is another object of the present invention to provide a thermostathaving an especially formed stirrup portion thereof which streamlinesthe flow of fluid when the thermostat is opened to minimize the pressuredrop in the upstream portion of the flow conduit.

It is another object of the invention to provide a thermostat assemblywhich permits the thermostat to be lockingly engaged with the upstreamconduit portion to avoid damage to the thermostat during assembly of theupstream conduit portion with the downstream conduit portion.

The invention may take physical form in certain parts and arrangement ofparts, a preferred embodiment of which will be described in detailherein and illustrated in the accompanying drawings which form a parthereof and wherein:

FIG. 1 is a sectional view of a thermostat mounted in a conduit andshown in an open position;

FIG. 2 is a top view of the thermostat in locking engagement with theupstream portion of the conduit with the upstream conduit shownpartially in section;

FIG. 3 is a side elevation view in section of the thermostat taken alongLine 3-3 of FIG. 2 and showing the thermostat in a closed position; and

FIG. 4 is a cross-sectional view of the stirrup portion of thethermostat taken along Line 44 of FIG. 3.

Referring now to the drawings wherein the showings are for the purposeof illustrating a preferred embodiment of the invention only and not forthe purpose of limiting same, FIG. 1 illustrates a thermostat l disposedwithin a flow conduit 12 which includes an upstream or low pressureportion 12" defined by an outlet casting 14 and adownstream or highpressure portion 12, defined by the engine water jacket 16.

Thermostat comprises a transverse wall piece 18 having a top andbottom-end 20 and 22 respectively from which extends an especiallyformed stirrup 24 and a base wall portion 26 respectively. Moreparticularly the transverse wall piece 18 is defined by an annularflange 28 at its bottom end 22 leading into an especially formedcylindrical seating section 30 which in turn leads into a frusto-conicalthroat section or valve seating surface 32in turn leading directly intoa cylindrical port wall 34.-

Disposed within and extending from both ends of the transverse wallpiece'18 is-a' thermal sensitive power unit identified by the numeral36. Power unit 36 includes a temperature sensing portion 38, an enlargeddiameter collar 40 formed'about the upper end of the sensing portion 38,a guide section 42 and a power member or piston 44 which is slideablewithin the guide section 42 and extensible from the guide uponpredetermined increases in ambient temperature sensed by the sensingportion 38.'Such thermal elements are well understood by those skilledin the art and the parts 38, 40, 42 are commonly referred to as thecasing 46.

The base wall portion'26 extending from the bottom end 22 of thetransverse wall piece 18 includes a pair of legs 48 shown staked at oneend to the transverse wall piece 18 and formed at their other ends intoan upwardly and inwardly extending cylindrical guide 50; the guide 50and legs 48xdefining a cylindrical recess 52 which functions as a seatfor one end of a compression spring 54. The guide 50 is positioned in anembracing relation to the temperature sensing portion 38 of the powerunit 36 and serves to guide the unit for rectilinear movement as theambient temperature of the sensing portion varies.

The opposing end of compression spring 54 abuts against a movable valvemember 56 which is defined by an inner annular outturned flange 58permanently affixed to the guide section 42 of power unit 36 and anouter annular valving section 60 which compresses spring 54-. Theannular valving section 60 is cooperable with the frusto-conical valveseating surface 32 to control the flow of coolant through thecylindrical port wall 34. I l

The stirrup 24 which is contiguous with and of the same material as thecylindrical port wall 34 constitutes an important part of the subjectinvention. Stirrup 24 comprises a pair of identically formed legportions 62 extending upwardly and angularly inwardly fromdiametrically-opposed points on the cylindrical port what into therecess 72 of power member 44 to assure that the power member 44 will notmove retractively; relative to the casting 46 and out of the apex 64.

The formed leg portions 62 shown in FIG. 4 are char- I acterized in thatthey possess a substantiallyclosed cross-section profile. This profileis defined by a straight outer surface 76 and side surfaces 78 appendingfrom the lengthwise rounded edges80 of the outer surface 76. The sidesurfaces 78 taper downwardly and inwardly to contact each other at theirfree ends 82 along a plane (shown as centerline 84 in FIG. 4) whichbisects the outer surface 76 i.e., at an angle X of 45 relative to thecenterline 84 of the outer surface 76.

This configuration of the formed leg portions 62 assures that theturbulent coolant flow shown as arrows in FIG. 1 will be streamlinedaround and immediately upstream of the stirrup 24. Thus directimpingement of i the coolant against the stirrups outer surface 76 whichresults in erosion and premature failure of the stirrup is avoided.importantly test results have shown that the streamlined flow patternresulting from the stirrup configuration produces a smaller pressuredrop in the up stream portion of the conduit 12" than that which occursin thermostats of identical construction not possessing the formedstirrup leg portions 62 of the present invention.

Referring now to FIG. 2 the seating section 30 of wall piece 18 is shownsubstantially circular having a nominal or minor diameter D-l. A pair ofdiametricallyopposed protrusions 88 extend from predetermined points onthe periphery of seating section .30 to define a major diametricaldistance D-2; the difference between D-1 and D-2 in the embodiment shownwithin a range of 0.025 inch to 0.035 inch. The outlet casting 14 has anelliptical opening 90 at the base thereof defined by a minor axis D-l'and a major axis D-2'; the

difference between D1 and D2' in the embodiment shown within a range of0.035 inch 0.045 inch and importantly D-l of opening 90 being at least0.015 inches smaller than the distance D-2 of the thermostat seatingsection 30.

The thermostat is initially placed in the outlet casting opening withthermostat minor and major diametrical distances D-1 and D-2 alignedwith the minor and major axes D-1' and D-2 of the outlet casting opening90 respectively. The thermostat 10 is then locked into place by twistingseating section 30 into an interference surfaces 96 tapering outwardlyto form an apex 98.

Thus the cylindrical seating section 30 of the transverse wall piece 18could be formed as an ellipse similar to that of the outlet casting 14to accomplish the desired locking action. Additionally the lockingengagement could be accomplished by designing the interference fitbetween the outlet casting l4 and the thermostat at any point on thetransverse wall piece 18 which does not interfere with the upstreamflow. Thus the protrusions 88 could be applied to the cylindrical portwall 34 of the transverse wall piece 18 if the outlet casting opening 90be similarly modified.

The present invention has been described with reference to a preferredembodiment. Obviously additional modifications and alterations willoccur to others upon reading and understanding of the specification. Itis my intention to include all such modifications and alterationsinsofar as they come within the scope of the present invention.

It is thus the essence of the invention to provide an improvedthermostat having an especially formed stirrup configuration to producestreamlined upstream coolant flow while also providing an especiallyformed wall piece section in combination within an especially formedoutlet conduit to assure accurate positioning of the thermostat withinthe flow conduit.

Having thus defined my invention, we claim:

1. A thermostat assembly for controlling the flow of fluid through aconduit comprising:

a generally cylindrical transverse wall piece having first and secondopen ends and defining a valve seat surface therein; power unit withinsaid wall piece, said power unit having a power member extending fromsaid first end and a casing portion extending from said second end;valve member affixed to said casing for common movement therewith andcooperable with said valve seat to open and close the flow of fluidthrough said thermostat;

a base wall member affixed to said wall piece and extending from saidsecond end, said wall piece having a guide opening for said casing and aspring support portion formed therein;

compression spring position between said valve member and said springsupport portion and normally biasing said valve member in a closedposition;

stirrup integral with and of the same material as said transverse wallpiece, said stirrup having at least two formed leg portions having anouter surface and side surfaces appending from the lengthwise edges ofsaid outer surface, said side surfaces tapering downwardly and inwardlyto contact each other at their ends along a line which bisects saidouter surface; and

means for securing said wall piece in said conduit.

2. A thermostat assembly as defined in claim 1 wherein said outersurfaces and said side surfaces of said formed portions are contiguouswith said apex and said surfaces of said apex are crimped about saidpower member to secure said power member within said apex.

3. A thermostat assembly as defined in claim 1 wherein said wall piececomprises an annular flange at said second end, an upwardly-extendingsleeve portion spaced radially-inwardly from and contiguous with saidflange, said sleeve portion having a generally circular periphery ofdiameter having a first distance and at least one portion of said sleeveextending outwardly from said periphery to define a second diametricaldistance, and an upstream portion of said conduit having a similarconfiguration as said sleeve portion for receiving said sleeve portion.

4. A thermostat assembly as defined in claim 3 wherein said upstreamportion of said conduit has first and second diametrical distancessimilar to that of said sleeve portion and said sleeve portion is lockedinto engagement with said conduit portion by aligning said seconddiametrical distance of said sleeve portion with said first diametricaldistance of said conduit portion.

5. A thermostat assembly for mounting a thermostat in a conduit tocontrol the flow of fluid therein, the assembly comprising:

a thermostat having a transverse wall piece, a base wall member securedthereto to define an opening therebetween, and a power unit disposed insaid opening, said wall piece having an annular flange and a sleeveportion spaced radially-inwardly of said flange and contiguoustherewith, said sleeve portion extending perpendicular to said flangeand having a generally circular periphery with at least one protrusionextending therefrom;

an outlet gasket defining the upstream portion of said conduit having anelliptical base opening receiving said sleeve portion in tightengagement therewith; and

fastening means for mounting said thermostat in said outlet gasket bycompressing said flange in a sealing manner.

6. A thermostat assembly as defined in claim 5 wherein said ellipticalopeninghas a minor axis of distance greater than said diameter of saidsleeve portion but less than the diametrical distance of said sleeveportion between said protrusion'whereby said thermostat is locked inpredetermined position in said outlet castmg.

1. A thermostat assembly for controlling the flow of fluid through aconduit comprising: a generally cylindrical transverse wall piece havingfirst and second open ends and defining a valve seat surface therein; apower unit within said wall piece, said power unit having a power memberextending from said first end and a casing portion extending from saidsecond end; a valve member affixed to said casing for common movementtherewith and cooperable with said valve seat to open and close the flowof fluid through said thermostat; a base wall member affixed to saidwall piece and extending from said second end, said wall piece having aguide opening for said casing and a spring support portion formedtherein; a compression spring position between said valve member andsaid spring support portion and normally biasing said valve member in aclosed position; a stirrup integral with and of the same material assaid transverse wall piece, said stirrup having at least two formed legportions having an outer surface and side surfaces appending from thelengthwise edges of said outer surface, said side surfaces taperingdownwardly and inwardly to contact each other at their ends along a linewhich bisects said outer surface; and means for securing said wall piecein said conduit.
 2. A thermostat assembly as defined in claim 1 whereinsaid outer surfaces and said side surfaces of said formed portions arecontiguous with said apex and said surfaces of said apex are crimpedabout said power member to secure said power member within said apex. 3.A thermostat assembly as defined in claim 1 wherein said wall piececomprises an annular flange at said second end, an upwardly-extendingsleeve portion spaced radially-inwardly from and contiguous with saidflange, said sleeve portion having a generally circular periphery ofdiameter having a first distance and at least one portion of said sleeveextending outwardly from said periphery to define a second diametricaldistance, and an upstream portion of said conduit having a similarconfiguration as said sleeve portion for receiving said sleeve portion.4. A thermostat assembly as defined in claim 3 wherein said upstreamportion of said conduit has first and second diametrical distancessimilar to that of said sleeve portion and said sleeve portion is lockedinto engagement with said conduit portion by aligning said seconddiametrical distance of said sleeve portion with said first diametricaldistance of said conduit portion.
 5. A thermostat assembly for mountinga thermostat in a conduit to control the flow of fluid therein, theassembly comprising: a thermostat having a transverse wall piece, a basewall member secured thereto to define an opening therebetween, and apower unit disposed in said opening, said wall piece having an annularflange and a sleeve portion spaced radially-inwardly of said flange andcontiguous therewith, said sleeve portion extending perpendicular tosaid flange and having a generally circular periphery with at least oneprotrusion extending therefrom; an outlet gasket defining the upstreamportion of said conduit having an elliptical base opening receiving saidsleeve portion in tight engagement therewith; and fastening means formounting said thermostat in said outlet gasket by compressing saidflange in a sealing manner.
 6. A thermostat assembly as defined in claim5 wherein said elliptical opening has a minor axis of distance greaterthan said diameter of said sleeve portion but less than the diametricaldistance of said sleeve portion between said protrusion whereby saidthermostat is lockEd in predetermined position in said outlet casting.